The joint interest of Danuser and Horwitz is to identify mechanisms by which mechanical forces and chemical signals integrate to regulate cell migration. One central question in our labs is how cell external and cell internal forces at integrin-mediated cell matrix adhesions change composition, structure and signaling properties of adhesion sites. The key challenge in addressing this question is the nested feedback interaction between force production, adhesion strengthening (also referred to as adhesion reinforcement), and adhesion signaling (Fig 1). In this scenario, conventional perturbation experiments, where one component is changed and resulting phenotype is interpreted in the context of the intervention, provide limited information about the interdependence of the processes. Therefore, our labs will implement a strategy that requires minimal perturbation. We will use live-cell imaging approaches to simultaneously measure the basal activities of multiple processes and apply statistical signal processing to derive from this data the hierarchy and kinetics of the relations between activities. Predictions from this non-perturbing approach will then be tested by acute mechanical simulation and tracking of molecular activities that lead to adhesion strengthening and signaling.